NIPT检测技术在血清学筛查结果为高风险的非高龄孕妇中的应用

The application of NIPT detection technology in serological screening for high risk non senior pregnant women

目的探讨用无创产前基因检测(NIPT)对血清学标志物筛查结果为高风险的非高龄孕妇(18-34岁)进行产前诊断的意义。方法回顾性分析2015年2月到2017年2月在嘉兴市妇幼保健院就诊的非高龄妊娠孕妇3629例,通过母体外周血中检测胎儿游离DNA,应用NIPT产前基因检测技术得出胎儿患染色体非整倍性疾病(21-三体综合征、18-三体综合征、13-三体综合征)的风险率。并对高风险胎儿采取羊水或脐血,再行细胞培养染色体核型分析以确定胎儿染色体核型,个别病例用微阵列比较基因组杂交技术(array—CGH)验证,对所有检测孕妇胎儿均随访至出生后。结果 NIPT检测结果显示共有29例孕妇为高风险,阳性率为0.80%,≥25岁阳性率为0.82%,年龄<25岁阳性率为0.50%;其中22例21三体综合征(I21),3例18三体综合征(T18),4例l3三体综合征(T13),14例性染色体异常;经胎儿核型分析证实为20例T21,2例核型正常;2例T18,1例T13,11例性染色体异常。所有检测孕妇胎儿出生后的随访中没有发现假阴性。经统计分析胎儿NIPT检测21-三体综合征的阳性符合率为90.90%、18-三体综合征的阳性符合率为66.67%和13-三体综合征的阳性符合率为25%;T21、T18、T13胎儿的敏感性分别为100%、100%、100%;假阳性率0.17%。结论 NIPT检测用于血清学筛查结果为高风险的非高龄孕妇检测可减少侵入性的产前诊断,但存在一定的假阳性,仍需有创检查进行确诊。

Objective：To explore the significance of noninvasive prenatal gene detection（NIPT）for prenatal diagnosis of high-risk pregnant women（18-34 years old）with high risk of serological markers screening. Methods：A retrospective analysis from February 2015 to February 2017 in Jiaxing Maternal and Child Health-Care Center for treatment of senile non pregnant women in 3629 cases,the detection of free fetal DNA in maternal peripheral blood,aneuploidy disease using NIPT prenatal detection technology that the fetus with chromosome（18-syndrome,trisomy 13-trisomy 21-trisomy comprehensive risk）. Fetal chromosomal karyotype was determined by karyotype analysis of fetal fetuses and umbilical cord blood,and the karyotype of fetus was determined. Microarray comparative genomic hybridization（array CGH）was used to verify individual cases. All fetuses were followed up until after birth.Results：NIPT results showed that a total of 29 cases of pregnant women with high risk,the positive rate was 0.80%,the positive rate of more than 25 years old age25 years was 0.82%,the positive rate was 0.50%;22 cases of trisomy 21（I21）,3 cases of trisomy 18（T18）,4 cases of trisomy L3 syndrome（T13）,14 cases of sex chromosome abnormalities;through the fetal karyotype analysis confirmed 20 cases of T21,2 cases of normal karyotype;2 cases of T18,1 cases T13,11 cases of sex chromosome abnormalities. No false negative was found during the follow-up of all pregnant women who had been tested. Through the statistical analysis of fetal NIPT detection of trisomy 21-syndrome the positive coincidence rate was 90.90%,18-trisomy syndrome,the positive coincidence rate was 66.67% and 13-trisomy syndrome,the positive coincidence rate was 25%;the sensitivity of T21,T18,T13 of the fetus were 100%,100%,100%;the false positive rate was 0.17%. Conclusion：NIPT detection can reduce invasive prenatal diagnosis for serological screening high-risk pregnant women. However,there is a false positive result,and invasive examination is still needed for diagnosis.